1. Field of the Invention
The present invention relates to a simplified and small motor vehicle which includes two front wheels and at least one rear wheel.
2. Description of Relevant Art
A motorcycle equipped with a prime mover having a small size and a small displacement is generally well known in the art. The motorcycle of this type includes those which are similar to a bicycle or a scooter. However, a motorcycle of either of such types is provided with only two wheels, and thus cannot be driven by those who are unable to ride a bicycle.
As a light vehicle, on the other hand, a tricycle equipped with a prime mover has found general acceptance. Such a tricycle has a larger size, a more complex construction, and a greater weight than a two-wheeled motorcycle or a scooter, and the displacement or the stroke volume of the prime mover is accordingly increased so that it exceeds the scope of a small and simple vehicle.
There has developed a desideratum for a vehicle having three or four wheels, which can be driven without any difficulty by those who are unable to ride a bicycle, and which satisfies the conditions of small size and weight as well as simplicity. In attempting to provide such a vehocle at a cost comparable to that of a bicycle, however, there arises a number of problems to be solved with respect, for example, to the frame, engine and suspension of the vehicle with a view toward ensuring sufficient riding comfort, maneuverability, drivability and operability.
In the case of a small-size light motor vehicle having two front wheels and one or two rear wheels, it is preferable to obtain the drivability and operability characteristics which are similar to those associated with a bicycle. To this end, the height of the seat of a driver is preferably set such that he can set and place his legs upon steps, while bending his legs substantially at a right angle about his thighs in a manner similar to the position he would assume were he to ride on a bicycle, without being required to stoop down. Thus, it is also preferred that the driver can normally set his feet on the steps and can stretch his legs to the road similar to the case of a bicycle. In this regard, moreover, the legs of the driver have to be protected sufficiently during the running operation of the vehicle. However, if the steps are extended excessively, a driving feeling similar to that of a bicycle decreases, which should be avoided in view of drivability and operability considerations. On the other hand, if the drivability and operability similar to that of a bicycle is considered to be an indispensible condition notwithstanding the fact that the vehicle has three or four wheels, sufficient consideration has to be taken with respect to the steering mechanism.